Lapaluet

Lapaluet, the plural form of lapaluu, are the scapulae or shoulder blades. They are flat, triangular bones located on the posterior aspect of the thorax, each forming part of the shoulder girdle. In humans, they lie over the ribs from about the second to the seventh and are connected to the clavicle at the acromioclavicular joint and to the humerus at the glenohumeral joint.

The scapula has several key features. The spine of the scapula runs across the posterior surface and ends laterally in the acromion, which forms part of the shoulder joint. The coracoid process projects anteriorly as another attachment point for muscles. The shallow glenoid cavity articulates with the head of the humerus, while the subscapular, supraspinous, and infraspinous fossae provide muscle attachment areas. The scapula has a superior border and a medial (vertebral) and lateral (axillary) border, with acute superior and inferior angles.

Functionally, the scapula serves as a stable platform for arm movement, providing attachment sites for muscles such as the rotator cuff group, deltoid, and various back muscles. Its mobility—through rotational and translational movements of the scapulothoracic articulation—complements glenohumeral motion to allow a wide range of shoulder movements while protecting the thoracic cage.

Development and variation: scapulae ossify from multiple centers during adolescence and can show anatomical variation among individuals and species. Clinical relevance includes conditions like scapular winging from nerve injury, scapular fractures after trauma, or dyskinesis affecting shoulder mechanics.

See also: shoulder girdle, clavicle, humerus, rotator cuff.